1. Technical Field
The present disclosure relates to the detection of metals in a fluid such as water or air. The present disclosure relates in particular to the detection of pollution by heavy metals.
2. Description of the Related Art
Certain metals produced by human activity are rejected into nature and cause pollution of the water or of the air. Certain metals such as arsenic, cadmium, chromium, copper, mercury, nickel, lead, and zinc effect health and the biosphere. It is therefore desirable to detect the presence of such metals.
In the semiconductor component manufacturing industry, certain manufacturing steps use ultrapure water. It is therefore also desirable in this domain to be able to detect the presence of metals in the water used in order to prevent any metallic contamination of manufactured components.
Among the known detection and analysis methods are spectrometry methods by absorption or by plasma emission, methods based on the fluorescence under the effect of X-rays, and colorimetric methods. These methods require expensive equipment as well as the sampling and transport of water samples to a laboratory where the samples may be analyzed. Certain analysis methods require pre-treatments such as filtration and the addition of chemical additives. These methods have the disadvantages of being long, expensive, and unreliable due to the non-negligible risk of sample contamination during their transport, storing, or pre-treatment.
Electrochemical detection and analysis methods also exist that are in-situ, that is to say that they do not require transport and storing of samples, nor pre-treatment. These methods measure one or more electrical characteristics of a sample, such as the intensity of a current traversing the sample, the voltage between electrodes inserted in the sample, and the electrical resistance of the sample. The detection or the analysis is done from the measured electrical characteristics.
Recently, electrochemical microsensors formed in a film have also been developed.